1. Field of the Invention
The present invention relates to the field of computer systems. More specifically, embodiments of the present invention relate to a method and apparatus for supplying power to a portable computer system and to a peripheral device.
2. Related Art
As the components required to build a computer system have reduced in size, new categories of computer systems have emerged. One of the new categories of portable computer systems is the “palmtop” computer system. A palmtop portable computer system is a computer that is small enough to be held in the hand of a user and can be “palm-sized.” Most palmtop computer systems are used to implement various Personal Information Management (PIM) applications such as an address book, a daily organizer and electronic notepads, to name a few.
Because of the limited size of palmtop portable computer systems, battery power is typically limited to one or two AAA or smaller batteries. This limits the operations that can be performed by the palmtop portable computer system.
The latest generations of palmtop portable computer systems are enhanced with the capability of coupling to a variety of peripheral devices. This gives their user access to a large amount of additional features. However, peripheral devices often use quite a lot of power. Therefore, many peripheral devices often include their own power source such as, for example, rechargeable batteries.
The use of a portable computer system and a peripheral device that is connected to the portable computer system can be limited by either the batteries in the peripheral device running out of charge or the batteries in the portable computer system running out of charge. In many instances the batteries in the peripheral device run out before the batteries in the portable computer system. The user must then discontinue usage of the peripheral device, even when there is significant charge left in the batteries of the portable computer system. Also, the batteries in the portable computer system can run out before the batteries in the peripheral device. The user must then discontinue usage of the portable computer system, even when there is significant charge left in the batteries of the peripheral device.
What is needed is a method and apparatus for controlling operating time of a portable computer system and a peripheral device. Also, a method and apparatus is needed that maximizes operating time of the portable computer system and the peripheral device.